Fibrotic diseases can be found in a variety of tissues. For example, Peyronie's disease (PD) is a fibromatosis (Hellstrom and Bivalacqua, 2000; Schwarzer et al., 2001; Jarow et al., 1997; Devine et al., 1997) of the tunica albuginea (TA), the specialized lining of the corpora cavernosa of the penis. Clinically, this usually leads to penile deformation (curved penis during erection), pain, and quite frequent erectile dysfunction. Fibrotic disease can also be found in other tissues, for example, pulmonary fibrosis, liver fibrosis, renal fibrosis, and vascular fibrosis.
It has been indicated that PD plaques and/or other fibrotic conditions can be pharmacologically arrested or reduced in size, by decreasing collagen synthesis and inducing myofibroblast apoptosis (Gonzalez-Cadavid et al., U.S. Pat. No. 8, 133,903). Oral administration of a nonspecific PDEi, e.g., pentoxifylline, has been suggested to be useful in reducing collagen levels in Peyronie's Disease plaques (Brant et al., Nature Clinical Practice Urology 2006, Vol 3, p. 111; Smith et al., Asian Journal of Andrology 2011, Vol 13, p. 322; Safarinej ad et al., BJU International 2010, Vol 106, p. 240). However, oral pentoxifylline has been shown to have moderate to minimal improvement.
Therefore, there remains a need for treatment of fibrotic diseases, e.g., Peyronie's disease.